Method for producing resin acid esters



ALAIN" C. SGEIQETQIJ,

PAR Y, I

14*, PATENT @FFlLQE' Tiifii'i, IVEW JEIWEY, ASSIGNOR TO HEEGULES POWDER COM G-IJQN, DELAWARE, A CORPORATION 036 DELAWAJEllt IIZSIilLi'EiIfiII EQR PRODUCING RESIN ACID ESTERS Ho Brewing".

as of wood and gum rosin.

In accordance with my invention, I subject a resin acid, as such, or at present in a resin, to treatment with an alcohol, which will effect esterification of the resin acid, in

31g. the presence of an esterification catalyst comprising a sulfonic acid.

In the practical adaptation of my invention the resin acid which may, as has been indicated, be pimaric acid, abietic acid, etc.,

15 as such, or as found in resins, as, for example,

wood rosin in the case of abietic acid, is subjected to treatment with an alcohol such, for example, as an aliphatic alcohol, which, for example, may be methyl ethyl, propyl,

n-butyl, amyl, isopropyl, a glycol, glycerol,

alcohols containing a mug, such as benzyl, cyclohexanol. or the like. The treatment is effected in the presence of heat and in the presence of a sulfonic acid, which will operate as an esterification catalyst, as for example, a sulfonic acid soluble in the alcohol used. The sulfonic acid may be, for example, para-toluene sulfonic acid, benzene sulfonic acid, naphthalene sulfonic acid, sulphosalicylic acid, napthol sulfonic acid, naphthionic acid, etc., etc. Desirably, the sulfonic acid Will be used in amount of about 3% of the resin acid to be esterfied. The treatment may be desirably carried out under pressure.

As illustrative of the practical adaptation of my invention, for example, methyl abietate may be prepared by heating abietic acid, as such, or in the form of Wood or gum rosin, say 480 g. of wood rosin, with say 480 g. of methanol (methyl alcohol) in the presence of, say, 15 g. of para-toluene sulfonic acid. The treatment may be at a temperature of C.,under a pressure of about 275 lbs. for a period of say four hours. When the treatment is completed, excess methanol is distilled off, under atmospheric pressure, and say 10 g. of soda ash added to neutralize the catalyst after which the ester (methyl abietate) may be distilled oil", under reduced pressure. In the example given about 415 g.

application filed January 24, 1980. Serial No. 423,265.

of methyl abietate, acid number 6, or a yield of about 87% will be obtained.

As further illustrative, for example, ethyl abietate may be produced by heating 320 g.

of wood rosin and 500 g. ethyl alcohol in the presence of 10 g. sulfonic acid, as p-toluene sulfonic acid, for a period of four hours at a temperature of about 160 C. under a pressure of about Has, the ester, ethyl abietate, being distilled off, after removal of excess alcohol and neutralization of the catalyst with soda ash. In the example about 240 of ethyl abietate, or a yield of about 73%, will be obtained. If desired, the time required in the above example may be reduced, with some reduction in yield. Thus, for example, by heating,to a temperature of about 235 C. under a pressure of about 650 lbs. for about one hour a yield of 200 g. of ethyl abietate will be obtained.

As further illustrative, for example, ethyl abietate may be produced by autoclaving 320 g. of rosin, 500 g. of 92% ethyl alcohol and 10 g. of beta naphthalene sulphonic acid, as a catalyst, at a temperature of 160 C. for about four hours. When the treatment is completed excess alcohol is distilled ofl under atmospheric pressure and soda ash added to neutralize the beta. naphthalene sulphonic acid catalyst and the ethyl abietate distilled off under reduced pressure. The ethyl abietate produced amounts to about 245 g. acid number 15. In the example given beta naphthalene sulphonic acid may be replaced, for example, with sulfosalicylic acid as the catalyst and with such substitution there will be obtained about 210 g. of ethyl abietate, acid I number 12. The ester may be redistilled over soda ash, if desired, with production of an ethyl abietate having an acid number of about 2.

As further illustrative, various esters as of n-butyl abietate and amyl abietate may be prepared by heatingone mol rosin with ten mols n-butyl or amyl alcohol in the presence of a sulfonic acid, at, for example, a temperature of about 200 (1, under a pressure of about 200 lbs., for four hours, for the production of n -butyl abietate and at a temperature of about 0., under a pressure of theoretically,

about 17 lbs., for four hours for the produc tion of amyl abietate, a yield as high as 90% being obtainable.

As illustrative of the adaptation of my 1nvention to the preparation of the ester with the use of glyco for example, about 320 parts of wood rosm, grading 1 m color, and about 310 parts of ethylene glycol are heated to ture is raised to about 300 C. under a pressure of about inch of mercuryto permit glycol, rosin, etc. to distill off. The product glycol diabietate will amount to about 285 20 goarts acid No. 1. If desired, gl cerol may substituted for glycol in the a ove'exam:

ple, the temperature being raised to about 250 C.

It will be noted inconnection with the process embodying this invention that while in the case of abietic ac1d, one mol of abietic acidwill react with one mol of alcohol to form the ester, it is desirable to use a substantial excess of alcohol, say for example, five mole, and for higher yields say ten mols as indicated.

It will now be understood that the method according to my invention involves broadly the treatment of a resin acid with an al 1- phatic alcohol in the presence of a sulfomc acid for the production of a resin ester.

What I claim and desire to protect by Letters Patent is: Y

1. Themethod of preparing an ester of a natural resin acid which includes heating a resin acid with an aliphatic alcohol in the presence of a sulfonic acid. 2. The method of preparin an ester of a resin acid which includes heating abietic acid with an aliphatic alcohol in the presence of a sulfonic acid.

3. The method of preparing an ester of a resin acid which includes heating rosin with an aliphatic alcohol in the presence of a sulfonic acid. I

4. The method of preparing-an ester of a natural resin acid which includes heating under pressure a resin acid with an aliphatic alcohol in the presence of asulfonic acid.

5. The method of preparing an ester of a 55 resin acid which includes heating under pressure abietic acid with an aliphatic alcohol in the presence of a sulfonic acid.

6. The method of preparing an ester of a resin acid which includes heating under pressure rosin with an aliphatic alcohol in the presence of a sulfonic acid.

7. The method'of natural resin acid w ich includes heating a resin acid with an aliphatic alcoholin the presence of about 3% of a sulphonic acid.

preparing an ester of a 8. The method of preparing an ester of i a resin acid which includes heating abietic acid with an aliphatic alcohol in the presence of about 3% of a sulfonic acid. v

9. The method of preparin an ester of a resin acid which includes eating resin with an aliphatic alcohol in the presence of about 8% of a sulfonic acid.

10. The method of preparing an ester of a natural resin acid which includes heating a resin acid with an aliphatic alcohol in the presence of para-toluene sulfonic acid.

11. The method of producing the butyl ester of a natural resin acid whlch includes heating a resin acid with butyl alcohol in the presence of a'sulfonic acid.

12. The method of producing the butyl ester of a natural resin acid which includes heating a resin acid with but 1 alcohol in the presence of para-toluene su ionic acid.

13. The method of producing the butyl ester of a resin acid which includes heating rosin with butyl alcohol in the presence of a sulfonic'acid.

- 14 The method of producing the butyl ester of a resin acid which includes heatin under pressure resin with but 1 alcohol in t e presenie5 of ara-toluene su fonic acid. a natural resin acid w ic includes heating a resin acid with an aliphatic alcohol'in the resence of a sulfonic acid which is soluble in the alcohol.

16.The method of producin the butyl ester of a resin which includes eating at a temperature of about 200 C. under pressure rosin with butyl alcohol in the presence of para-toluene sulfonic acid.

17. The method of preparing an ester ofa resin acid which includes heating rosin with an aliphatic alcohol in thepresence of paratoluene sulfonic acid.

18. The method of pre aring an ester of a resin acid which inclu es heating abietic acid with an aliphatic alcohol in the presence of para-toluene sulfonic acid.

19. The method of preparing an ester of a resin acid which includes heating one mole abietic acid with ten moles aliphatic alcohol in the presence of a sulfonic ac1d..

In testimony of which invention, I have hereunto set my hand at Kenvil, N. J on this 22nd day of January 1930.

ALAN o. JOHNSTON.

e method of re aring an ester of 

